Telecommunications systems connect users at geographically dispersed locations. The public switched telephone network (PSTN) evolved around providing a narrow-band medium for carrying voice traffic between users. More recently, the PSTN has been used to carry data to and from computers that connect to the PSTN with modems. These modems typically carry data with bit rates of up to 56 Kbps.
The integrated services digital network (ISDN) was developed to carry higher bandwidth traffic over the existing local loop facilities of the PSTN. This network allows voice or data to be carried in digital form from user to user over the network. Various protocols or modes exist for transporting data over an ISDN network. Thus, the existing networks provide means for transporting telecommunications signals of a number of different modes between users. These modes are, essentially, incompatible and conventional equipment is typically dedicated to a specific telephone number such that a specific device only receives signals of a designated mode.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for circuits and methods for handling a variety of signal modes with a single number.